Abstract: The invention provides a method for extracting nucleic acids from a sample. The sample contains cells, viruses, or both cells and viruses. The method include adding a lysing solution containing a detergent to the sample to lyse the cells or viruses to form a lysate, adding alcohol to the lysate to aggregate or precipitate the nucleic acids, and purifying the nucleic acids from the lysate-alcohol mixture by filtering the mixture through a glass-fiber filter.